Polyethylene terephthalate (PET) bottles are commonly used in the United States as containers for beverages. Prior to filling a bottle with a liquid beverage for human consumption, the bottles undergo a sterilization process.
One method of sterilizing bottles as part of a continuous bottling system is to use liquid sterilant, wherein the bottles are filled with liquid sterilant to sterilize the interior of the bottle, and then rinsed to remove any excess or residual sterilant. Filling and removing a sterilant and rinse solution from a bottle requires that the bottles be repeatedly inverted and returned to an upright position. Rotating bottles from an upright position to an upside down position and vice versa increases the complexity and cost of a continuous bottling system.
Moreover, bottles are typically rinsed with sterilized water, which requires a system for generating the sterile water. Sterile water is expensive to produce, and the sterility level of the water is always suspect.
Another method of sterilizing bottles uses condensed hydrogen peroxide (H2O2). In these systems, the H2O2 is first vaporized and then condensed onto the cooler surface of the bottles. The H2O2 sterilant is typically a mixture of water and hydrogen peroxide. A problem with using condensed vaporized hydrogen peroxide (VHP) systems is that it is difficult to obtain uniform condensation coverage on complex bottle surfaces that may have temperature gradients there along. It is also difficult to determine the concentration of concentrated vaporized hydrogen peroxide that is necessary to reach the condensation point due to variations in both bottle temperature and humidity levels.
The present invention overcomes these and other problems and provides a system for decontaminating bottles and the like as part of a continuous bottle-filling system, wherein a centralized vaporized hydrogen peroxide system provides and controls the concentration of VHP to a bottling system.